Process for moving food objects through a frying tank

ABSTRACT

A small, inexpensive doughnut fryer has a conveyor and separate elevator that are driven from the same shaft without interference with one another. Sprockets for driving the elevator are recessed to receive rods from the conveyor. The entire conveyor assembly is provided with a quick release coupling to the power supply. A method and apparatus for moving objects to be fried through a hot frying liquid by producing intermittent waves and eddies in the liquid in the desired direction of travel to propel the objects in a straight line.

This application is a divisional application of application Ser. No.770,849, filed Aug. 29, 1985 now U.S. Pat. No. 4,628,804.

DESCRIPTION

1. Technical Field

This invention pertains to doughnut frying machines and, moreparticularly to improvements in conveyors and drive mechanisms for suchfrying machines. In addition, the invention pertains to methods andapparatus for moving objects to be fried through a hot liquid in afrying tank.

2. Background Art

Frying machines, particularly those for frying small doughnuts or otherfood objects, must be easy for the operator to use and to clean at theend of a frying operation. In addition, these machines tend to be soldin high volumes, at low cost and must have a minimum number ofcomponents to be marketable. A machine is disclosed in U.S. Pat. No.4,346,649 which accomplishes some of these objectives. This invention isan improvement of the machine in U.S. Pat. No. 4,346,649.

A difficulty in moving objects to be fried through the hot frying liquidof a frying tank is that the heating element at the bottom of the tankcreates eddy currents in the liquid which causes the objects being movedthrough the liquid to circulate in irregular paths. This moves theobjects out of a straight alignment transverse to the desired path ofmovement through the frying tank. The objects then tend to bunch up andbecome jammed within the conveyor. When the objects are brought to aflipper to invert the objects for frying the uncooked side of theobject, the flipping is not successfully accomplished if the objects arenot perfectly aligned in a transverse row when they reach the flipper.

DISCLOSURE OF INVENTION

It is one of the objects of this invention, therefore, to move theobjects through the liquid in a straight transverse row. It wasdiscovered that by imparting intermittent wave motions to the liquid,that the wave motion would propel the objects forward in a row andovercome the cross motions caused by heat eddy currents. It was alsodiscovered that by using a bar conveyor that created a wave at theleading edge of the pushing bar, that simultaneously an eddy pullingcurrent or a void-type pulling action was produced at the trailing edgeof the next forward bar. This combination then of a rearward pushingwave and a forward pulling current, if done intermittently through thelength of the frying tank, keeps the floating objects alignedconsistently in a transverse row so they are in optimum alignment whenthey reach the flipper and do not tend to become out of alignment at anyarea in the tank.

The improvements to the conveying apparatus are basically to drive a barconveyor for pushing the doughnuts through the frying tank from the sameshaft that a belt type elevator conveyor is driven. This reduces thedrive mechanisms necessary for the conveyor and the elevator. Thesprockets for the bar conveyor and the elevator that are coupled to thecommon shaft are uniquely modified so that the conveyor sprockets can beof different pitch circles giving the elevator a slightly faster speedthan the bar conveyor, but which enable the bars of the bar conveyor tomove around the common shaft without interfering with the sprockets forthe belt elevator. Thus it is a unique feature of this invention toprovide a bar conveyor that overlies an endless belt elevator, both ofwhich are driven from a common shaft, but at different speeds and withthe bars being able to pass around the shaft and the sprockets for thebelt elevator without interference.

Another unique improvement of the conveyor and tank system is a couplingwhich enables the entire conveying system to be lifted as an integralunit out of the frying tank while simultaneously decoupling the drivingshaft from the power supply from the driven shaft of the conveyor andelevator with one simple sliding movement. This greatly simplifies theconstruction of the machine and greatly simplifies and makes safer thedisassembly of the machine for cleaning at the end of each operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded, isometric view of a frying machine embodying theprinciples of the invention.

FIG. 2 is an enlarged, isometric view of a portion of the frying machinecapable of carrying out the process of the invention.

FIG. 3 is a fragmentary cross-section through the driven shaft of theconveyor system.

FIG. 4 is a schematic illustrating the simplified mechanism fordisconnecting the driven shaft and the integral conveyor and elevatorassembly from the driving shaft of the power supply.

BEST MODE FOR CARRYING OUT THE INVENTION

The fryer comprises a base 10 in which is fitted a removable frying tank12. Liquid is kept hot in the frying tank by a heating element 14coupled to a control console 16. A conveyor assembly 18 is alsoremovably fitted into the tank 12 and is drivingly coupled to thedriving shaft 20 of a power supply within the console 16.

The details of operation and construction of the basic components of thefrying machine are shown in U.S. Pat. No. 4,346,649, the description ofwhich is incorporated herein by reference thereto. Doughnuts or otherobjects to be fried are dropped from a hopper or cutter (not shown) intothe inlet or left end of the frying tank (as viewed in FIG. 1). Thecutter deposits the doughnuts at one or more laterally spaced locationsin the tank generally in a transverse row. The doughnuts are movedthrough the tank, inverted, and then removed for cooling.

The conveyor assembly 18 includes a pair of side frames 24 (FIG. 2)coupled together by spacer bars 26. Mounted within the side frames is anelongated bar conveyor 28 having two endless chains 29 with a pluralityof pusher bars 30, spaced equidistantly along the runs of the endlesschains.

An elevator link belt 32 is also mounted in the side frames and runsparallel to an upwardly inclined section of the conveyor 28. The bars 30thus move up in parallelism and slightly above the elevator belt.

It is a unique feature of this invention that both the conveyor 28 andthe elevator belt 30 are driven by sprockets mounted on a common shaft36. This shaft is provided with a set of belt sprockets 40 (FIG. 3) anda set of conveyor sprockets 38. The belt sprockets are slightly largerin circular pitch so as to move the belt 32 at a slightly increasedvelocity over the velocity of the conveyor.

As best shown in FIG. 3, the sprockets 40 are each cut away with arecess 42. The recesses 42 are all coaligned. The bars 30, as they reachthe top of the elevator belt and come into engagement with the sprockets38, move into the recesses 42 so that they do not actually engage anysurface of the sprockets 40. This enables the bar to move rotationallyrelative to the sprockets 40, but not interfere with the motion of thesprockets. Thus the common simplified, inexpensive drive is suitable foroperating two separate conveyors at two separate speeds withoutinterference with one another.

Another unique feature of the invention is the way the entire conveyorassembly can be removed and decoupled from the driving shaft 20. As bestshown in FIGS. 2 and 4, the driving shaft is provided with a ball 48 anda radial protruding pin 49. The driven shaft 36 is provided with asocket 50 having an opening 52 and an elongated, longitudinal slot 54.When the conveyor socket and the driving shaft ball are in the positionas shown in FIG. 4, the entire conveyor assembly can be lifted as oneintegral unit and slid out from driving engagement with the drivingshaft. The ball enables the socket to rotate clockwise as shown in FIG.4, and the pin is free to slide within the slot until the conveyorassembly can then be moved to the left, as shown by the arrow 56 and thedrive is disengaged. To reengage the drive the opposite motion isemployed. This greatly simplifies the drive disconnection for ease ofcleaning and reassembling.

A flipper mechanism 60 is employed essentially as in U.S. Pat. No.4,346,649. The flipper includes a channel 62 which is engaged by thebars 30. The bar 30 as it then moves past the flipper rotates theflipper to invert a doughnut in the frying liquid. A cam 64 is providedwith a flattened surface against which rests a weighted arm 66. The armrests on the flat surface of the cam to position the flipper in perfectalignment, as shown in FIG. 2. After a doughnut has been inverted andthe flipper falls back, the weighted arm guides the cam to restore thealignment position of the flipper.

A unique feature of the invention is the technique by which doughnutsare moved through the hot liquid without bunching up or becomingmisaligned out of a transverse row as they approach the flipper. Theheating element 14 creates fluid currents within the frying liquid.These currents tend to be circular and will impart a motion to theobjects floating in the frying liquid tending to move then out of theirinitial transverse alignment. In this invention the drive to the drivingshaft 20 is accomplished by a conventional electric AC motor which isoperated through a timing switch such that the motor is operated onlyafter a certain interval and in a repetitive manner. Thus the drivemoves at a constant speed but intermittently. The intermittent motion istimed to correspond to the dropping of doughnuts or other objects to befried into the gap between two bars, the objects being dropped in atransverse row. As the first intermittent pulse of movement occurs, thenext rearwardmost bar creates a forwardly moving wave in the hot liquid.This wave impels the doughnuts forwardly toward the next most forwardbar. The force is strong enough to overcome any crosscurrents created bythe hot eddy currents in the liquid.

It is also found that the forward motion of the next forwardmost barcreates a small eddy pulling current or forwardly directed void whichpulls the forwardly moving doughnuts toward the next forwardmost bar.This action results in the doughnuts being advanced from rearward bar toforward bar with each impulse with the doughnuts seldom moving very farrearwardly, but rather tending to follow the forward movement of thenext forward bar. It has been found that this motion, particularly forsmaller objects where there are several aligned in a row, uniquely keepsthe objects in the transverse row while they are moved completly throughthe conveyor, including the alignment as they are brought intoengagement with the flipper.

In overall operation, the hopper is swung back and forth across the tankand is coupled to a link 70 that is moved in synchronysm with therotation of the driven shaft 36. The hopper thus deposits the doughnutdough into the gap between two bars. Upon the next intermittent pulse ofmovement, the conveyor bars push the doughnuts forwardly to the right,as seen in FIG. 2. As the doughnuts reach the flipper, the nextforwardmost bar causes the flipper to invert the doughnuts. The barscontinue to propel the doughnuts to the elevator belt 32 where they areraised out of the liquid and where they may drain excess liquid.Finally, the elevator belt deposits the doughnuts on a take-away ramp74.

As is apparent from the foregoing, the machine is very easy to use, easyto assemble and disassemble, and inexpensive to manufacture. Thetechnique by which the doughnuts are moved through the frying liquidwithout bunching greatly improves the operation of the machine. Whilethe details of the machine and process have been described, it should beunderstood that variations will be apparent to one skilled in the artwithout departing from the principles herein. Accordingly, the inventionis not to be limited to the specific embodiment illustrated herein.

We claim:
 1. A process for moving small food objects through a hotliquid in a frying tank by a pusher bar conveyor having spaced pusherbars, comprising:heating the liquid in the tank to a frying temperatureand creating liquid currents in the liquid; placing the objects into theliquid in front of the bars of the conveyor; and intermittently movingthe bars at a generally constant speed through the liquid, for creatingrepetitive wave motions in the liquid to push the objects toward thenext forward bar and overcoming the heat created liquid currents in theliquid thereby moving the objects in a straight path through the liquidto avoid misalignment.
 2. The process of claim 1, said step ofintermittently moving the bars including creating an eddy pullingcurrent behind the next most forward bar to draw the objects forwardtoward the next most forward bar with each intermittent motion of thebars.